JP6174676B2 - Guidance tool for manually operating an endoscope using pre- and intra-operative 3D images and method of operating a device for guided endoscope navigation - Google Patents

Description

  The present disclosure relates to a medical device and more specifically to a guidance tool for manually operating an endoscope.

  Coronary artery bypass grafting (CABG) is a surgical procedure for revascularization of a blocked coronary artery. Minimally invasive CABG is performed using an endoscope as the only feedback from the surgical site. In a standard setting for minimally invasive CABG surgery, the surgeon holds the instrument with both hands while the assistant holds the endoscope. An endoscope is typically inserted into the thoracic cavity from the right side of the patient or from the anteroposterior direction. This can result in three related coordinate systems: an endoscope (eg, camera) coordinate system, a surgeon's coordinate system, and an assistant's coordinate system. This can lead to multiple problems. For example, while the surgeon is looking at the front screen, the camera shows the anatomy from the side. In addition, if the camera at the upper end of the endoscope is rotated 180 °, the image will appear reversed on the screen. However, there is currently no way to know the camera orientation. In addition, the assistant must respond to instructions from the surgeon on how to move the endoscope. A command such as “Right” may correspond to moving the endoscope to the left and down, which is very counter-intuitive to the assistant and can lead to a trial and error approach. These problems can lead to long operating room residence times and inefficiencies in the workflow.

  In accordance with the principles of the present invention, a new solution is provided for a guidance tool for manually operating an endoscope.

  In one embodiment, the principles of the present invention may include registering pre-operative and / or intra-operative images with endoscopic images. Visual cues can be overlaid on the endoscopic view as a guidance tool that allows the user to navigate the endoscope toward a selected region of interest. Endoscope movement can be tracked in real time using image features to update visual cues. In another embodiment, the principles of the present invention may pre-orient the endoscope camera such that the camera coordinate system corresponds to the user's preferred coordinate system. The endoscope camera may be mounted on an operating platform that pre-orients the endoscope by rotating the camera to correspond to the user's preferred orientation. Advantageously, the principles of the present invention provide an efficient operation for manually navigating the endoscope. This can lead to reduced operating room residence time and a more efficient workflow.

  A system for guided endoscopic navigation includes a registration module configured to register a first image set of an endoscope with a second image set using a processor. The selection module is configured to receive the selected region of interest on the first set of images and convert the selected region of interest into an endoscopic coordinate frame. The guidance module is configured to overlay a guidance tool on the second set of images to allow an endoscope user to navigate to a selected region of interest.

  A system for guided endoscopic navigation includes a registration module configured to register a first image set of an endoscope with a second image set using a processor. The selection module is configured to receive the selected region of interest on the first set of images and convert the selected region of interest into an endoscopic coordinate frame. The guidance module is configured to overlay the guidance tool on the second set of images. The actuation module is configured to direct the endoscope camera such that the camera coordinate system corresponds to the user coordinate system to allow the endoscope user to navigate to the selected region of interest. Is done.

  A method for guided endoscopic navigation includes registering a first image set of an endoscope with a second image set using a processor. A region of interest is selected on the first set of images, and the selected region of interest is converted to an endoscopic coordinate frame. A guidance tool is overlaid on the second set of images to allow the user of the endoscope to navigate to the selected region of interest.

  These and other objects, features and advantages of the present disclosure will become apparent from the following detailed description of example embodiments thereof read in conjunction with the accompanying drawings.

  The present disclosure presents in detail the following description of preferred embodiments with reference to the following drawings.

FIG. 3 is a block / flow diagram illustrating a system for manually operating an endoscope using a guidance tool, according to one embodiment. FIG. 3 is an example of an endoscopic image with overlayed direction, path and direction error indicators according to one embodiment. FIG. 6 is an example of an endoscopic image overlaid with a distance error indicator indicating distance according to one embodiment. FIG. 4 is an example of an endoscopic image overlaid with a distance error indicator using a virtual spring, according to one embodiment. FIG. FIG. 2 is a block / flow diagram illustrating a system for orienting an endoscope camera coordinate system with an endoscope user coordinate system, according to one embodiment. It is one Example of the endoscopic image which orient | assigns the coordinate system of an endoscope camera to the coordinate system of an endoscope user concerning one Embodiment. FIG. 5 is a block / flow diagram illustrating a method for manually operating an endoscope using a guidance tool, according to one embodiment.

  In accordance with the principles of the present invention, embodiments for systems, devices and methods provide guidance tools for manually operating an endoscope. In one embodiment, pre-operative and / or intra-operative images are registered with endoscopic images. Visual cues can be overlaid on the endoscopic view as a guidance tool that allows a user (eg, a surgeon's assistant) to manipulate the endoscope toward a selected region of interest. Endoscope movement can be tracked in real time using image features to update visual cues. Visual cues include, but are not limited to, a directional indicator that indicates the direction to the selected region of interest, an endoscopic tracer that indicates the movement of the endoscope, an endoscope compared to the direction to the selected region of interest A direction error indicator indicating the angular error of the movement, a distance error indicator indicating the distance to the selected region of interest, and an anatomical reference direction indicating the anatomical direction. Other visual cues are possible and are considered within the principles of the present invention.

  In another embodiment, the principles of the present invention may pre-orient the endoscopic camera coordinate system with the user's preferred coordinate system. In order to pre-orient the camera in a suitable direction, the endoscope camera can be mounted on a working platform. The endoscope user moves the endoscope in a physical direction that prefers to correspond, for example, to the “upward” direction in the image. The angle between the physical movement of the endoscope and the actual upward direction in the image is determined, and the actuation platform rotates the camera accordingly to pre-orient the coordinate frame. It is noted that the principles of the present invention are not limited to the upward direction and can include any direction.

  Although the present invention will be described with respect to an endoscope, the teachings of the present invention are broader and apply to any optical scope that can be utilized for internal viewing of bifurcated, curved, coiled, or other shaped systems. It should be understood that this is possible. In some embodiments, the principles of the present invention are utilized to track or analyze complex biological or mechanical systems (eg, digestive systems, circulatory systems, piping systems, passageways, mines, caves, etc.). In particular, the principles of the present invention can be applied to procedures in the entire region of the body such as internal tracking procedures of biological systems, lungs, gastrointestinal tract, excretory organs, blood vessels and the like. The elements depicted in the drawings can be implemented in various combinations of hardware and software and provide functionality that can be combined into a single element or multiple elements. The embodiments described herein are preferably displayed for view on a display monitor. Such monitors may include any suitable display device including, but not limited to, handheld displays (such as personal digital assistants, telephones, etc.), computer displays, televisions, dedicated monitors, and the like. Depending on the scope, the display can be provided as part of the system or can be a separate unit or device.

  It should also be understood that the optical scope may include a plurality of different devices connected to or associated with the scope. Such devices can include lights, cutting devices, brushes, vacuums, cameras, and the like. These components can be integrally formed with the distal tip of the scope. The optical scope can include a camera positioned at the tip of the scope, or the camera can be positioned at the end of the optical cable opposite the tip.

  The functions of the various elements shown in the figures can be provided using dedicated hardware and hardware capable of executing software in conjunction with appropriate software. When provided by a processor, functionality may be provided by a single dedicated processor, by a single shared processor, or by multiple individual processors, some of which may be shared. In addition, the explicit use of the word “processor” or “controller” should not be construed to represent exclusively hardware capable of executing software, but is not limited to digital signal processors. ("DSP") hardware, read only memory ("ROM") for storing software, random access memory ("RAM"), non-volatile storage, etc. may be implicitly included.

  Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. In addition, such equivalents are intended to include both presently known equivalents as well as equivalents developed in the future (ie, any element developed that performs the same function regardless of structure). Thus, for example, as will be appreciated by those skilled in the art, the block diagrams presented herein represent conceptual diagrams of exemplary system components and / or circuits that embody the principles of the invention. Similarly, it will be appreciated that any flowcharts, flow diagrams, and the like may be represented substantially on a computer-readable storage medium and by a computer or processor (whether or not such computer or processor is explicitly specified). Represents the various processes that can be performed as such.

  Furthermore, embodiments of the present invention take the form of a computer program product accessible from a computer-usable or computer-readable storage medium that provides program code for use by or in connection with a computer or any instruction execution system. obtain. For purposes of this description, a computer usable or computer readable storage medium is any that can contain, store, communicate, propagate, or transport a program for use by or in connection with an instruction execution system, device, or apparatus. Equipment. The medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. Examples of computer readable media include semiconductor or solid state memory, magnetic tape, removable computer diskettes, random access memory (RAM), read only memory (ROM), fixed magnetic disks and optical disks. Current examples of optical disks include compact disk-read only memory (CD-ROM), compact disk-read / write (CD-R / W), Blu-Ray (R), and DVD (R).

  In the drawings, like numerals represent the same or similar elements, and referring initially to FIG. 1, a system 100 for manually manipulating an endoscope using a guidance tool is illustratively depicted in accordance with one embodiment. System 100 includes a workstation or console 108 from which procedures (eg, endoscopy) are managed and controlled. The workstation 108 preferably includes one or more processors 138 and a memory 110 for storing programs and applications. It should be understood that the functions and components of the system 100 can be integrated into one or more workstations or systems.

  Memory 110 may store image 112. Image 112 includes pre-operative and intra-operative images, which may be received from systems including, but not limited to, magnetic resonance imaging (MRI) systems, computed tomography (CT) systems, x-ray systems, 3D ultrasound systems, and the like. The memory 110 may also store a scope image 114 received from the scope 102. In the preferred embodiment, the scope 102 is an endoscope that captures intraoperative images of the surgical site from the camera 106. Scope image 114 may preferably include video from camera 106 of endoscope 102.

  The principles of the present invention can be applied to different applications of endoscopic guided minimally invasive surgery. For example, the principles of the present invention include cardiac surgery (eg, minimally invasive coronary artery bypass grafting, atrial septal defect suture, valve repair / replacement, etc.), laparoscopic surgery (eg, hysterectomy, prostatectomy, gallbladder surgery, etc.) It can be used for natural orifice transluminal surgery, pulmonary / bronchoscopic surgery, neurosurgery interventions, and video-assisted chest surgery. However, the teachings of the present invention are much broader and scope 102 can include any type of scope for various types of applications. In one example embodiment, the principles of the present invention may be applied to manually navigate “plumber's snack” through a pipe. Other uses are also considered.

  The workstation 108 may include one or more displays 134 for viewing pre- and intra-operative images 112 and scope images 114 that include guidance features of the principles of the present invention. Display 134 may also allow a user to interact with workstation 108 and its components and functions. This is further facilitated by a user interface 136 that may include a keyboard, mouse, joystick, or any other peripheral device or control that allows the user to interact with the workstation 108.

  The computer implementation program 116 is stored in the memory 110 of the workstation 108. Program 116 may include a plurality of modules, each configured to perform various functions. It should be understood that modules can be implemented in various combinations of hardware and software.

  The program 116 may include a registration module 118 configured to perform registration between the image 112 (eg, preoperative and / or intraoperative image) and the scope (eg, endoscopic) image 114. Registration is performed as is well known in the art.

  Program 116 may also include a selection module 120 configured to allow a user (eg, a surgeon) to select a region of interest on pre-operative and intra-operative images 112 (eg, CT or x-ray). For example, the selected region of interest may be a target bypass artery in coronary artery bypass grafting. Selection module 120 may include the use of display 134 and user interface 136 to facilitate this selection. The selection module 120 then converts the selected region of interest using the registration transformation determined in the registration module 118 from a pre-operative and / or intra-operative image coordinate frame to an endoscopic coordinate frame.

  The program 116 may include a guidance module 122 configured to determine a plurality of guidance indicators using a selected region of interest within the endoscopic view. Guidance module 122 may include, but is not limited to, any or all of direction module 124, path module 126, and distance module 128. Other indicators are also considered.

  The direction module 124 determines the direction from the current center of the endoscopic image to the selected region of interest and overlays a direction indicator on the endoscopic image. With reference briefly to FIG. 2A, an endoscopic image including an overlaid indicator 200 is illustratively depicted in accordance with one embodiment. A direction indicator 206 is overlaid on the endoscopic image to indicate the direction from the center 202 of the endoscopic image to the selected region of interest 204.

  The guidance module 122 of FIG. 1 may include a path module 126 that further assists a user (eg, a surgeon or assistant) to navigate the endoscope. Referring back to FIG. 2A for a short time, an endoscopic trace 208 showing the movement of the endoscope is overlaid on the endoscopic image. Trace 208 is generated by tracking the position of one or more anatomical features located in the center of the endoscopic image and overlaying an arrow that marks the position on the endoscopic image. In each frame or frame period, the current feature at the center of the image is overlaid with an arrow on the endoscopic image while continuing to track the features that were previously at the center of the image. This process can be continued to create a visual trail that helps the user operate the endoscope to navigate to the selected region of interest 204.

  The direction of the trace 208 can be compared to the direction of the target region of interest 204 to display the angular error using visual cues. In one embodiment, dial 210 may be displayed using needles 212 and 214 that indicate an angular offset between the movement of endoscope 208 and the direction 206 of the selected region of interest, respectively. Other visual cues that indicate angular error are also considered. For example, the angle between the direction to the selected region of interest 206 and the movement of the endoscope 208 may be displayed (eg, in degrees).

  Guidance module 122 may also include a distance module 128 configured to indicate the distance from the center of the endoscopic image to the target region of interest. Referring briefly to FIG. 2B, an endoscopic image with a distance error indicator 220 overlaid is illustratively depicted in accordance with one embodiment. The endoscopic image may also include a direction indicator 206 that indicates the direction from the center 202 of the endoscopic image to the target region of interest 204. In one embodiment, distance 222 may be shown as a number on the screen (eg, in pixels). In another embodiment, a line between the center 202 of the endoscopic image and the selected region of interest 204 may be represented as a function of distance. For example, referring briefly to FIG. 2C, an endoscopic image 240 overlaid with a distance indicator using a virtual spring is illustratively depicted according to one embodiment. A virtual spring 242 connects the center 202 of the endoscopic image with the selected region of interest 204. The virtual spring may appear to expand as the distance between the two points further increases and to compress as the distance decreases. Other distance error indicators are also considered. For example, the color of the line between the center 202 of the endoscopic image and the selected region of interest 204 can vary with distance, and an explanatory text defining the color is displayed on the screen. In another embodiment, the line thickness can be modified as the distance changes.

  In yet another embodiment of the principles of the present invention, the direction module 124 of FIG. 1 may overlay an anatomical reference direction on the endoscopic image. Once the preoperative and intraoperative images 112 are registered with the endoscopic image 114 by the registration module 118, the anatomical reference directions of the preoperative and intraoperative images are determined. The anatomical reference direction is converted into an endoscopic coordinate system and overlaid on the endoscopic image. Anatomical reference directions may include, but are not limited to, anterior / posterior, right / left, and head / foot directions. Other anatomical directions are also considered.

  Using the overlaid guidance indicator of the guidance module 122, the user navigates the endoscope 102. To determine whether the endoscope 102 has reached the selected region of interest, the movement of the endoscope is traced as described above. The operation of the guidance module 122 is repeated until the selected region of interest is reached. When the selected region of interest is reached, the process ends.

  In one embodiment of the principles of the present invention, the program 116 of FIG. 1 may also include an activation module 130 that further assists the user in navigating the endoscope 102. The actuation module 130 is configured to pre-orient the camera 106 using the actuation platform 104 such that the camera coordinate system corresponds to the user's preferred coordinate system. The actuation module 130 receives the direction that the user prefers to correspond to, for example, the upward direction. For example, the user may physically move the endoscope in a preferred upward direction. The angle between the physical movement of the endoscope and the true upward direction of the endoscopic image is calculated and passed as input to the working platform, which pre-directs the camera accordingly. It is noted that the corresponding direction is not limited to the upward direction, but rather can include any direction.

  Referring now to FIG. 3A, a system for orienting an endoscope camera coordinate system with an endoscope user coordinate system 300 is illustratively depicted in accordance with one embodiment. The camera 106 is mounted on the working platform 104 on the scope 102. The actuation platform 104 rotates according to the received angle and directs the camera accordingly. Turning briefly to FIG. 3B, an example endoscopic image 320 overlaid with orientation indicators is illustrated according to one embodiment. The user moves the endoscope in the preferred upward direction, resulting in endoscope movement 324 from the image center indicator 202. The angle between the endoscope movement 324 and the true upward direction 322 of the image is calculated to determine an angle 326 that is passed to the actuation platform 104 to direct the camera accordingly.

  With reference now to FIG. 4, a method 400 for manually manipulating an endoscope using a guidance tool is illustratively depicted in accordance with one embodiment. At block 402, the scope image is registered with pre-operative and / or intra-operative images. The scope image is preferably an endoscope image including a camera that captures an intraoperative image of the surgical site. The endoscopic image may preferably include a video. Pre-operative and / or intra-operative images may be received from systems including but not limited to MRI systems, CT systems, x-ray systems, 3D ultrasound systems, and the like. Registration is performed as is well known in the art.

  At block 404, a region of interest may be selected on the pre-operative and intra-operative images. At block 406, the selected region of interest may be converted from pre-operative and intra-operative image coordinate frames to endoscopic image coordinate frames. This may include the use of registration transformations determined at block 402.

  At block 408, a direction from the current center of the endoscopic image to the selected region of interest is determined in the endoscopic image. Using this direction, at block 410, a guidance indicator is overlaid on the endoscopic image. Guidance indicators may include, for example, without limitation, direction indicators, endoscopic tracers, direction error indicators, distance error indicators, and anatomical reference direction indicators. Other indicators are also considered.

  In one embodiment, the guidance indicator may include a direction indicator overlaid on the endoscopic image to indicate the direction from the current center of the endoscopic image to the selected region of interest. In another embodiment, an endoscopic trace indicating the movement of the endoscope may be overlaid on the endoscopic image. The trace can be generated by tracking the position of each anatomical feature located at the center of the endoscopic image and overlaying an arrow marking that position on the endoscopic image. In each frame or frame period, the current feature at the center of the image is overlaid with an arrow on the endoscopic image, keeping track of the features that were previously in the center of the image. Continuing this process, the location of each feature is displayed in the endoscopic image to provide a visual trail that can help the user navigate the endoscope.

  In yet another embodiment, to determine an angular error that represents an angular offset between the movement of the endoscope and the direction to the selected region of interest, the endoscope trace is Can be compared. Angular errors can be overlaid on the endoscopic image using visual cues. In one embodiment, a dial containing two needles is overlaid on the endoscopic image, each needle indicating an endoscope trace and a direction to a selected region of interest, respectively. In another example, the angle error may be indicated by displaying the angle (eg, in degrees) on the endoscopic image.

  In one embodiment, the guidance indicator may include a distance error indicator overlaid on the endoscopic image. When the endoscope is moved, the distance from the center of the endoscopic image to the selected region of interest changes. The distance error can be overlaid on the endoscopic image to help the user navigate the endoscope. For example, distance may be indicated as the number of screens (eg, in pixels). In another embodiment, a line connecting the center of the endoscopic image and the selected region of interest may be represented as a function of distance. This can include representing the line as a virtual spring that can be stretched as the distance increases and compressed as the distance decreases. Alternatively, the color or thickness of the line can change according to the distance. Other representations of distance error are also considered.

  In another embodiment, the anatomical reference direction can be overlaid on the endoscopic image. Once the pre-operative and intra-operative images are registered (block 402), the anatomical reference direction of the pre-operative and intra-operative images is determined and converted to an endoscopic view. Anatomic reference directions may include, for example, anterior / posterior, right / left, and head / foot directions. Other anatomical reference directions are also considered.

  At block 414, the guidance indicator overlaid on the endoscopic image can be used to allow the user to navigate the endoscope more efficiently. The movement of the endoscope is tracked to determine if the selected region of interest is reached. If at block 416 the selected region of interest has not been reached, steps 408, 410, 414 and 416 are repeated until the selected region of interest is reached at block 418. Advantageously, the principles of the present invention help the user navigate the endoscope efficiently, resulting in reduced operating room residence time.

  In one embodiment of the present invention, at block 412, the endoscope camera may be pre-oriented so that the camera coordinate system corresponds to the user's preferred coordinate system. The user may indicate a preferred eg upward direction. This may involve the user physically moving the endoscope in the preferred upward direction. The angle between the physical movement of the endoscope and the actual upward direction of the endoscopic image is calculated and passed as input to the working platform that is mounted between the camera and the endoscope. The actuation platform rotates the camera according to the received angle to help the user navigate the endoscope. It is noted that the corresponding direction is not limited to the upward direction, but rather can include any direction.

In the appended claims:
a) the word “comprising” does not exclude the presence of other elements or acts than those listed in a given claim;
b) The word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements.
c) any reference signs in the claims do not limit their scope;
d) Multiple “means” may be represented by the same item or hardware or software implementation structure or function.
e) It is not intended that a specific order of operation is required unless otherwise specified.
It should be understood.

  While a preferred embodiment for a guidance tool for manually manipulating an endoscope using pre-operative and intra-operative 3D images has been described (illustrative and not limiting), in view of the above teachings It is noted that modifications and changes can be made by those skilled in the art. Accordingly, it is to be understood that changes may be made in certain embodiments of the disclosure that are within the scope of the embodiments disclosed herein as outlined by the appended claims. Having thus described the details and specificities required by the patent law, the scope of the claims to be protected by the patent certificate is set forth in the appended claims.

Claims (26)

A guidance system for endoscopic navigation,
A registration module that registers a first image set of the endoscope with a second image set using a processor;
A selection module that receives a selected region of interest on the first set of images and converts the selected region of interest into an endoscopic coordinate frame;
A guidance module overlaying a guidance tool on the second set of images to allow a user of the endoscope to navigate to the selected region of interest, the guidance module comprising: A system comprising a path module that overlays a path of current movement of the endoscope on a second image set.   The system of claim 1, further comprising an actuation module that directs the endoscope camera such that a coordinate system of the camera corresponds to a coordinate system of the user.   The system of claim 2, wherein the actuation module further rotates an actuation platform including the camera according to an angle between a first direction and an actual direction.   The system of claim 1, wherein the guidance module includes a direction module that overlays a direction indicator from a center of a frame of the second image set to the selected region of interest on the second image set.   The system of claim 1, wherein the path overlaid by the path module generates a visual trail of the movement of the endoscope.   Tracking an anatomical feature including at least one of the anatomical features located in the center of the frame of the second image set and a position of the anatomical feature previously located in the center of the frame; The system of claim 1, wherein the path is generated.   The system of claim 4, wherein the direction module further overlays an angular error indicator on the second image set that indicates an angular error between the direction indicator and the path of movement of the endoscope.   The distance module of claim 1, wherein the guidance module includes a distance module that overlays a distance indicator on the second image set indicating a distance from a center of a frame of the second image set to the selected region of interest. System.   The system of claim 8, wherein the distance indicator is a line from the center of the frame that varies with distance to the selected region of interest.   The system of claim 9, wherein the line is a virtual spring that appears compressed as the distance decreases and expands as the distance increases.   The system of claim 9, wherein the color of the line varies with distance.   The system of claim 1, wherein the guidance module includes a direction module that overlays the anatomical direction of the first image set on the second image set. A guidance system for endoscopic navigation,
A registration module that registers a first image set of the endoscope with a second image set using a processor;
A selection module for receiving a selected region of interest on the first set of images and converting the selected region of interest into an endoscope coordinate frame;
A guidance module including a path module that overlays a guidance tool on the second image set and overlays a path of current movement of the endoscope on the second image set;
In order to allow the user of the endoscope to navigate to the selected region of interest, the endoscope camera is oriented so that the camera coordinate system corresponds to the user coordinate system. A system having an actuating module attached.   The system of claim 13, wherein the actuation module further rotates an actuation platform including the camera according to an angle between a first direction and an actual direction of the first direction. A method of operating a device for guided endoscope navigation comprising:
Registering a first image set of an endoscope with a second image set using a processor;
Overlaying on the second image set a guidance tool that allows a user of the endoscope to navigate to a region of interest, the region of interest being selectable on the first image set, A method capable of being converted to an endoscopic coordinate frame,
The method of operating an apparatus for guided endoscope navigation, wherein the overlaying step includes overlaying a path of current movement of the endoscope on the second set of images.   16. The method of claim 15, further comprising directing the endoscope camera such that the camera coordinate system corresponds to the user coordinate system.   The method of claim 16, wherein the directing includes rotating an actuation platform including the camera according to an angle between a first direction and an actual direction of the first direction.   16. The method of claim 15, wherein overlaying comprises overlaying a direction indicator from the center of the frame of the second image set to the selected region of interest on the second image set.   16. The method of claim 15, comprising overlaying the path of the current movement of the endoscope on the second set of images but generating a visual trail of the movement of the endoscope. .   An anatomical feature that includes at least one of the anatomical features located in the center of the frame of the second image set, and the location of the anatomical feature previously located in the center of the frame. 16. The method of claim 15, wherein the method is generated by tracking.   19. The method of claim 18, wherein overlaying includes overlaying an angular error indicator on the second image set that indicates an angular error between the direction indicator and the path of motion of the endoscope. .   16. Overlaying comprises overlaying a distance indicator on the second image set indicating a distance from a center of a frame of the second image set to the selected region of interest. Method.   23. The method of claim 22, wherein the distance indicator is a line from the center of the frame that varies with distance to the selected region of interest.   24. The method of claim 23, wherein the line is a virtual spring that appears compressed as the distance decreases and expands as the distance increases.   24. The method of claim 23, wherein the color of the line varies with distance.   The method of claim 15, wherein overlaying comprises overlaying the anatomical direction of the first image set on the second image set.

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